In conventional steering lock devices of this kind, there is known one disclosed in JP 2009-248843 A. FIG. 17 illustrates a constitution of a conventional electric steering lock device 101. The conventional electric steering lock device 101 includes a lock member 150 for prohibiting a steering shaft (not illustrated) from rotating. The lock member 150 is arranged so as to be movable between a locked position where a tip of the lock member 150 projects from a frame 110 and an unlocked position where the tip is housed in the frame 110.
The conventional electric steering lock device 101 includes an auxiliary lock device 160 including a trigger 171, a trigger urging member 172, an auxiliary lock member 161, an auxiliary lock urging member 162, and an auxiliary lock receiving part 151f. In the auxiliary lock device 160, when a frame cover 120 is detached from the frame 110, the trigger 171 drops off due to an urging force of the trigger urging member 172, so that the engagement between the trigger 171 and the auxiliary lock member 161 is released and then, the auxiliary lock member 161 engages with the auxiliary lock receiving part 151f of the lock member 150 due to an urging force of the auxiliary lock urging member 162.
Owing to such an installation of the auxiliary lock device 160, even if the frame cover 120 is fraudulently detached under a lock state that the lock member 150 is located in the locked position, the conventional electric steering lock device 101 is capable of maintaining its steering lock state because the lock member 150 is held in the locked position.